Use el.innerHTML = ''; instead of $(el).empty()
Use el.innerHTML = ''; instead of $(el).empty()

It turns out that jQuery's empty method can be really slow in Firefox,
which can freeze the browser when cleaning the log.

fauxton/travis-web,fotinakis/travis-web,travis-ci/travis-web,fauxton/travis-web,fauxton/travis-web,travis-ci/travis-web,travis-ci/travis-web,travis-ci/travis-web,fotinakis/travis-web,fotinakis/travis-web,fauxton/travis-web,fotinakis/travis-web